Contact trigger release needle guard

ABSTRACT

A needle guard device mountable to a pre-filled syringe in its ready-to-fill state. The device includes a lock collar and a device shield biased to move relative to the lock collar. The lock collar interfaces with the syringe neck to attach the device to the syringe. With the removal of a needle shield assembly comprising rigid and soft needle shields, the lock collar and device shield are free to move proximally along the syringe neck and interact with a syringe step down area to activate the device. As the device moves proximally, retention arms of the device shield interact with the syringe step down, causing the arms to deflect radially outwards to disengage from the lock collar triggering the device shield to move from a first position to a second position.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/556,674, filed Nov. 7, 2011.

FIELD

The embodiments provided herein relate generally to safety systems forsyringes, and more particularly to a needle guard for a syringe thatincludes an automatically activated shield for covering a needle of thesyringe.

BACKGROUND INFORMATION

Medication is often dispensed using a medicine cartridge, such as aglass syringe, having a barrel with a needle at one end and a plungerslidably inserted into the other end and coupled to a rubber stopper.Such cartridges are often referred to as “pre-filled syringes” becausethey may contain a specific dosage or volume medication when they areinitially provided, as compared to conventional syringes that arefurnished empty and filled by the user before making an injection.

The glass syringe and rubber stopper have, for years, provided an idealdrug storage closure having unique properties of impermeability tooxygen, low extractables, biocompatability, durability, etc. However,they are both formed by processes that do not lend themselves to tightgeometrical tolerances. Tight tolerances were not originally needed bythese devices because they were not used mechanically with otherdevices.

Due to the risk of communicable diseases, a number of syringes andadapters have been developed that are intended to prevent accidentalneedle sticks and/or inadvertent reuse of a syringe. Conventionalpassive anti-needle stick safety devices for prefilled syringes mustmount to the syringe but not interfere excessively with the forcerequired to move the plunger rod during injection nor prevent the fulltravel of the plunger rod. The safety mechanism necessarily must betriggered toward the end of administration of the drug (near the end ofthe plunger rod travel). However, since virtually all safety deviceslocate the syringe against the safety device at a point under thesyringe finger flange, the operability of the safety device tends to bedependent on the tolerances of the syringe and stopper.

In addition, because conventional passive anti-needle stick safetydevices for prefilled syringes tend to mount to or on the barrel of thesyringe, the safety devices tend to obscure the contents of the syringeand must be applied post filling of the syringe.

Prefilled syringes tend to be shipped to pharma customers asready-to-fill syringes, which are ones that have been thoroughly cleanedinside and outside after the forming processes and attachment of aneedle and then placed in sealed tubs that are then sterilized andshipped to the pharma customers ready for filling with a medicine. Thesyringe tubs may contain 100 to 160 syringes each with a geometricalspacing and access that is consistent with established syringe handlingequipment. A safety device applied to the syringe must not obscure theoptical inspection systems that are in place to check the syringes priorto filling them with medication.

Accordingly, it would be desirable to have a needle guard for a syringehaving the safety device triggering mechanism independent of the syringeand stopper tolerances, and that assembles to the syringe withoutadversely affecting the syringe position with respect to the syringehandling tub or the way the handling equipment conveys the syringesduring filling and packaging nor impedes the inspection processes.

SUMMARY

The systems and methods described herein are directed to a needle guardfor a syringe having the safety device triggering mechanism independentof the syringe and stopper tolerances. A contact trigger release needleguard device described herein is an anti-needle stick device designed tobe attached to the distal end of a ready-to-fill syringe. The needleguard device includes a lock collar and a device shield moveablerelative to the lock collar. The device shield is biased relative to thelock collar by a spring. The lock collar interfaces with a syringe neckand bulbus to attach the needle guard device to the ready-to-fillsyringe. With the removal of a needle shield subassembly comprisingrigid and soft needle shields, the lock collar and device shield arefree to move proximally along the syringe neck and interact with thesyringe step down area triggering the device shield to move relative tothe lock collar from a first position, where a syringe sharp such as aneedle is exposed, to a second position where the needle is shielded orcovered.

In use, a device user removes the needle shield subassembly, inserts thesyringe sharp, such as a needle, into an injection site and pushes downon the syringe past the point of initial contact of the device shieldwith the skin, and up to the point where the lock collar and deviceshield have moved proximally along the syringe neck until the lockcollar is prevented from moving further proximally by the syringe stepdown. As the needle guard device moves proximally along the syringeneck, retention arms of the device shield interface with the syringestep down to deflect outwards to disengage from the lock collartriggering the device shield to move under a bias to the second orneedle shielded position.

In an alternative embodiment, both tactile and audible feedbacksignaling device activation is incorporated into the needle guarddevice. A feedback system includes feedback arms, which are pushedpassed feedback tabs during device activation preferably as theretention arms are disengaged from the lock collar.

In another alternative embodiment, the lock collar may be verticallyfixed to the syringe and include a lock collar ring with lock collartabs that can freely slide relative to the lock collar.

Other systems, methods, features and advantages of the invention will beor will become apparent to one with skill in the art upon examination ofthe following figures and detailed description.

BRIEF DESCRIPTION OF THE FIGURES

The details of the invention, including fabrication, structure andoperation, may be gleaned in part by study of the accompanying figures,in which like reference numerals refer to like parts. The components inthe figures are not necessarily to scale, emphasis instead being placedupon illustrating the principles of the invention. Moreover, allillustrations are intended to convey concepts, where relative sizes,shapes and other detailed attributes may be illustrated schematicallyrather than literally or precisely.

FIG. 1 is an exploded isometric view of a needle guard device with aready-to-fill syringe.

FIG. 2 is a partial section view of the needle guard device with thesyringe in the fully assembled pre-loaded state prior to use.

FIG. 3 is a partial isometric view of the needle guard device attachedto the syringe in the fully assembled pre-loaded state prior to use.

FIG. 4 is a partial section view of the needle guard device with thesyringe neck through the lock collar stop tabs in the fully assembledpre-loaded state prior to use.

FIG. 5 is an isometric view of the lock collar showing the lock collarretaining arms for retention to the syringe bulbus.

FIG. 6 is a bottom view of the lock collar.

FIG. 7 is an isometric view of the needle guard device without thesyringe in the fully assembled pre-loaded state prior to use.

FIG. 8 is a bottom view of the needle guard device showing thecompressible tabs of the soft needle shield.

FIG. 9 is a partial section view of a needle shield subassemblycomprised of a soft needle shield and a rigid needle shield.

FIG. 10 is a partial section view through the passive retaining arms ofthe device shield showing the connection of the rigid needle shield tothe device shield and the sealing surface of the soft needle shieldagainst the bulbus of the syringe.

FIG. 11 is an isometric view of the needle guard device showing thesequential progression of the removal of the needle shield subassembly.

FIG. 12 is an isometric partial section view of the needle guard devicewith the needle shield subassembly removed and illustrates the abilityof the needle guard device to move proximally along the syringe neckduring needle insertion via a gap between the lock collar and syringestep down area.

FIG. 13 is an isometric partial section view of the needle guard devicewith the syringe sharp inserted into an injection site with the deviceshield initially touching the injection site.

FIG. 14 is an isometric partial section view of the needle guard devicewith the syringe sharp completely inserted into the injection site withflex arms bent outward as a result of their interaction with the syringestep down area and the lock collar is positioned all the way up thesyringe neck in contact with the syringe step down.

FIG. 15 is an isometric partial view of the needle guard device and thesyringe with the needle shield subassembly removed and showing anaudible and tactile feedback arm integrated with the needle guarddevice.

FIG. 16 is an isometric partial section view through the feedback armsof the needle guard device with the syringe sharp inserted into theinjection site and the device shield initially touching the injectionsite, prior to safety activation of the needle guard device.

FIG. 17 is an isometric partial section view through the feedback armsof the needle guard device with the syringe sharp completely insertedinto the injection site and the needle guard device activated. Thefeedback arms are shown bent outward due to their interaction with thesyringe step down area during needle insertion, with the feedback armears pushed past the device shield angled tabs.

FIG. 18 is an isometric partial view of the needle guard device afterthe safety device has been activated with the flex arms and flexiblefeedback arms bent outward and syringe fully inserted into the injectionsite.

FIG. 19 is a partial section view of the needle guard device through thelock collar tabs showing the retention arms bent outward after fullsyringe sharp insertion with the retention arms in contact with theangled surface of the lock collar tabs enabling the device shield tofreely move relative to the collar distally along the syringe to shieldthe syringe sharp as it is extracted from the injection site.

FIG. 20 is an isometric partial section view of the needle guard devicethrough the lock collar tabs as the syringe is extracted from theinjection site and the syringe sharp is almost completely removed as thespring acts on the device shield to keep it against the injection siteas the syringe is removed and the retention arms move distally along thelock collar tabs.

FIG. 21 is an isometric partial section view of the needle guard devicethrough the lock collar tabs after the syringe sharp has been fullyretracted from the injection site and the retention arms have resiledinto place under the lock collar tabs to prevent the device shield frommoving proximally and locking the device shield in the second positionin a needle stick safe state.

FIG. 22 is an enlarged isometric partial section view of the needleguard device through the lock collar tabs after the syringe sharp hasbeen fully retracted from the injection site and the retention arms haveresiled into place under the lock collar tabs to prevent the deviceshield from moving proximally and lock the needle guard device in afully needle stick safe state.

FIG. 23 is an isometric partial view of the needle guard device afterthe syringe sharp has been fully retracted from the injection site andthe retention arms have resiled into place under the lock collar tabs toprevent the device shield from moving proximally.

FIG. 24 is an isometric partial section view of an alternate embodimentof the needle guard device depicting a lock collar which remains fixedto the syringe neck and a lock collar ring containing the lock collartabs that is freely slidable relative to the lock collar.

FIG. 25 is an isometric partial view of the syringe lock collar and lockcollar ring assembled to a syringe.

FIG. 26 is an isometric partial section view through lock collar tabs ofan alternate rigid needle shield embodiment depicting a syringe with anelongated syringe neck, a rib on the syringe neck for retention of alock collar, and a standard rigid needle shield.

FIG. 27 is a section view of an alternate soft needle shield embodimentwhich creates a seal around the bulbus of the syringe rather than agasket type seal against the bottom of the bulbus. The seal around thebulbus also acts to retain the rigid needle shield to the device byfriction.

DETAILED DESCRIPTION

The systems and methods described herein are directed to a needle guardfor a syringe having the safety device triggering mechanism independentof the syringe geometry. Turning now to the figures, FIGS. 1-23 show anembodiment of a contact trigger release needle guard. The needle guarddescribed herein is an anti-needle stick safety device designed to beattached to the distal end of a prefilled syringe in its ready-to-fillstate. As depicted in FIG. 1, the needle guard device 13 which couplesto a syringe 6 (depicted in its ready-to-fill state), is comprised offive (5) parts which include: a lock collar 1, a compression spring 2, adevice shield 3, a rigid needle shield 4, and a soft needle shield 4.

As depicted in FIGS. 2-4, the needle guard device 13 is delivered to theend user in a pre-loaded state, with the spring 2 compressed between thedevice shield 3 and lock collar 1. The lock collar 1 has two lock tabs 7on each side, which, as shown in FIG. 3, fit within two openings orcutouts 8 in each of the retention arms 9 of the device shield 3. Asdepicted in FIG. 4, the seat area 27 of the retention arms 9 rest on thehorizontal surface 26 of the lock collar tabs 7, in the pre-loadedstate, which lock the lock collar 1 and device shield 3 assemblytogether in a first position with a syringe sharp 17 extending beyondthe distal end of the device shield. The force of the compression spring2 holds the assembly in tension. As depicted in FIGS. 5 and 6, the lockcollar 1 contains four pads 10 internally located at the ends of lockcollar retaining arms 35, which, as shown in FIGS. 2 and 4, interfacewith the syringe neck 11 and bulbus 12 to attach the needle guard device13 to the syringe 6. The inner diameter of the lock collar 1 is definedby the lock collar pads 10 and are of a similar diameter to the base ofthe syringe neck 11 but less than the diameter of the bulbus 12.Consequently, during assembly of the needle guard device 13 onto thesyringe 6, the lock collar pads 10 force the lock collar retaining arms35 to flex over the bulbus 12 and relax around the syringe neck 11 forretention of the device 13 on the syringe 6 as shown in FIGS. 2 and 4.

The rigid needle shield 4, comprised of a thermoplastic, and the softneedle shield 5, comprised of an elastomer, as shown in FIGS. 3, 7, 8,and 9 are locked with each other vertically via compressible tabs 14located at the distal end of the soft needle shield 5. The soft needleshield 5 may be inserted into the rigid needle shield 4 by forcefullypushing the distal end of the soft needle shield 5 through the smallerdiameter opening in the rigid needle shield 4. The rigid needle shield 4and soft needle shield 5 subassembly 18 is releasably attached to thedevice shield 3 via flexible retaining arms 15 and an annular ring 16 onthe proximal end of the rigid needle shield 4 as shown in FIG. 10. Whenassembled to the device shield 3, the soft needle shield 5 interfereswith and compresses against the bulbus 12 of the syringe 6 creating aseal, which keeps the sharp (needle) 17 of the syringe 6 as well as thecontents of the syringe 6 sterile prior to removal of the needle shieldsubassembly 18. At the distal end of the soft needle shield 5. thesyringe sharp 17 protrudes into the elastomer material protecting thetip 17 a of syringe sharp 17.

Prior to performing an injection, a device user forcefully pulls out theneedle shield subassembly 18, as shown in FIG. 11, pulling the annularring 16 past the retaining arms 15. With the needle shield subassembly18 removed from the needle guard device 13, as shown in FIG. 12, thelock collar 1, device shield 3, and spring 2 are free to move proximallyalong the syringe neck 11. As depicted in FIG. 12, there is a small gap19 between the lock collar 1 and a stepped down area 20 of the syringe6, which allows for such proximal movement. When the needle shieldsubassembly 18 is in place, as depicted in FIG. 10, such proximalmovement along the syringe neck 11 is deterred due to the connectionbetween the rigid needle shield 4 and the device shield 3, as well asthe compression contact between the syringe bulbus 12 and the softneedle shield 5.

When performing an injection as shown in FIGS. 13 through 21, a deviceuser first inserts the syringe sharp 17 into an injection site 21. Theuser pushes down on the syringe 6 past the point of initial contact ofthe device shield 3 with the skin S as shown in FIG. 13, and up to thepoint where the lock collar 1, spring 2 and device shield 3 have movedproximally along the syringe neck 11 until the lock collar 1 abuts thesyringe step down 20 as shown in FIG. 14. Referring to FIGS. 14, 18 and19, as the needle guard device 13 travels proximally along the syringeneck 11, chamfered rib 34 (FIG. 14) of the retention arms 9 of thedevice shield 3 interact with the syringe step down 20, causing theretention arms 9 to flex or deflect radially outwards. The user willknow at this point that the safety device is activated because theretention arms 9 of the device shield 3 are bent radially outward fromthe needle guard device 13.

Additionally, as depicted in FIGS. 15-18, it is also possible toincorporate both tactile and audible feedback of device activation intothe needle guard device 13 by means of feedback arms 22, which arecaused to flex and push through angled tabs 23 present within the deviceshield 3 during device activation as the syringe sharp 17 is insertedinto the injection site 21. As the syringe sharp 17 is inserted into theinjection site 21 and the device shield 3 travels proximally along thesyringe neck 11, the feedback arms 22, as shown in FIG. 16, interactwith the syringe step down area 20 via a chamfered surface 25,deflecting the feedback arms 22 radially outward. As the feedback arms22 push outward as shown in FIGS. 16-18, the feedback arm ears 24contact and push past the device shield angled tabs 23 creating audibleand tactile feedback that the needle guard device 13 has been activated.

When the retention arms 9 of the device shield 3 have been flexedradially outward as described above, the retention arm seat areas 27lose contact with the top horizontal surface 26 of the lock collar tabs7, and move into contact with an angled outer surface 28 of the lockcollar tabs 7 as shown in FIG. 19. Consequently, once the user hasfinished their injection and begins to remove the syringe sharp (needle)17 from the injection site 21, as shown in FIG. 20, the device shield 3,which is released from the lock collar 1 and biased by the spring 2 tomove relative to the lock collar 1, travels distally from a firstposition toward a second position along the axis of the syringe 6,remaining in contact with the skin S around the injection site 21, andshielding the syringe sharp (needle) 17. Once the user has sufficientlyremoved the syringe sharp 17 from the injection site 21 and the syringesharp 17 is completely shielded, but just prior to releasing the deviceshield 3 from contact with the skin S around the injection site 21, thedevice shield retention arms 9 snap into a locked position with the lockcollar 1 as shown in FIGS. 21-23 to prevent proximal movement of thedevice shield 3 relative to the lock collar 1. At the proximal end ofthe device shield 3 are lock seat areas or cutouts 29 formed in theretention arms 9, which the lock collar tabs 7 fit within. As a result,at the end of the distally directed travels of the device shield 3, theretention arms 9 lose contact with the angled surface 28 of the lockcollar tabs 7 and are free to resile into a vertical position where thetop surface 30 of the lock seat area 29 of the retention arm 9 fitsunder the bottom surface 31 of the lock collar tab 7. Accordingly, ifany contact occurred with the device shield 3 to push it proximallyalong the syringe 6, the device shield 3 would be prevented from movingproximally, protecting the user and others from an accidental needlestick injury. An upper surface 32 of the lock seat areas 29 of thedevice shield 3 contacts the top surface 33 of the lock collar tabs 7and prevents the device shield 3 from being pulled distally off of thelock collar 1.

During needle 17 insertion and device activation, there are severalcontributors to the user force requirement for device activation. Notconsidering the force required for the needle 17 to be inserted into thepatient, the forces potentially include, depending on the embodiment;the force required to bend or deflect the device shield retention arms9, the force required to bend or deflect and activate the device shieldfeedback arms 22, and the force required to push the lock collar 1proximally along the syringe neck 11. In the embodiment discussed above,in which the lock collar retaining arms 35 with lock collar pads 10engage with the syringe bulbus 12 for retention of the needle guarddevice 13 to the syringe 6, the lock collar 1 must slide proximallyalong the syringe neck 11 upon insertion of the needle 17 in the patientin order to activate the needle guard device 13. Since the syringe neck11 is tapered, being narrower near the bulbus 12 and larger near thebarrel, the lock collar retaining arms 35 will need to flex duringsyringe insertion and device activation, adding to the force required toactivate the needle guard device 13. It may be desirable to furtherreduce the syringe insertion and device activation force, which can beaccomplished using the arrangement shown in FIGS. 24-25.

In the embodiment depicted in FIGS. 24-25, a lock collar 101 isvertically fixed to the syringe 106 and lock collar tabs 107 areintegrated into a lock collar ring 140 which can freely slide relativeto the lock collar 101. In this embodiment, during syringe insertion anddevice activation, the lock collar ring 140 moves proximally with thedevice shield 103 until the device shield retention arms 109 flex ordeflect enough radially to disengage with the lock collar ring tabs 107.At this point, the spring 102 would be free to push the device shield103 over the syringe sharp 117. The lock collar 101 would remain fixedto the syringe neck 111 and not add to the force necessary to activatethe safety device.

In another embodiment shown in FIG. 26, a rigid needle shield may beused which may be considered a “standard” rigid needle shield, or onewhich is currently marketed and often used on glass, pre-filled syringesto protect the needle and drug, such as, e.g., the Stelmi rigid needleshield or the Becton Dickinson (BD) rigid needle shield. In thisembodiment of a needle guard device 213, a lock collar 201 is attachedto an elongated syringe neck 211 by means of a rib 240 on the syringeneck 211 and lock collar pads 210 located on the inner diameter of thelock collar 201. The inner diameter of the lock collar pads 210 is lessthan that of the outer diameter of the syringe neck rib 240. Duringassembly the lock collar 201 is forced over the syringe neck rib 240thereby, retaining the lock collar between the syringe neck rib 240 andthe syringe neck down area 241. An elastomeric portion 251 of a rigidneedle shield 250 seals against a bulbus 212 of the syringe 206 as astandard rigid needle shield typically does. Additionally, the rigidneedle shield 250 protrudes from the device shield 203, which isslidably coupled to the lock collar 201 sufficiently enough to allow auser to easily grab and remove it from the needle guard device 13.

In another embodiment shown in FIG. 27, rigid needle shield 340,comprised of an outer thermoplastic 341 and an inner elastomer 342 isattached to the needle guard device 313 via friction between a neck 343of the inner elastomer 342 and the syringe bulbus 312 of the syringeneck 311, and between a distal solid end 344 of the inner elastomer 342and a syringe sharp 317. The friction interfaces described above alsoserve to protect the syringe sharp 317, create a seal between thesyringe sharp 317 and the inner elastomer 342 to protect the drug fromcontaminants, and create a seal between the syringe bulbus 312 and innerelastomer 342 to protect the outer wall of the syringe sharp 317 fromcontaminants.

In the foregoing specification, the invention has been described withreference to specific embodiments thereof. It will, however, be evidentthat various modifications and changes may be made thereto withoutdeparting from the broader spirit and scope of the invention. Forexample, the reader is to understand that the specific ordering andcombination of process actions shown in the process flow diagramsdescribed herein is merely illustrative, unless otherwise stated, andthe invention can be performed using different or additional processactions, or a different combination or ordering of process actions. Asanother example, each feature of one embodiment can be mixed and matchedwith other features shown in other embodiments. Features and processesknown to those of ordinary skill may similarly be incorporated asdesired. Additionally and obviously, features may be added or subtractedas desired. Accordingly, the invention is not to be restricted except inlight of the attached claims and their equivalents.

What is claimed is:
 1. A needle guard couplable to a ready-to-fill syringe, the ready-to-fill syringe including a body, a step down region at a distal end of the body, and a neck extending from the step down region, the needle guard comprising a lock collar couplable to a neck of a ready-to-fill syringe, and a device shield biased to move relative to the lock collar from a first position in which a syringe sharp extends beyond the device shield to a second position in which the syringe sharp is covered by the device shield, the lock collar and device shield being configured to engage to prevent movement of the device shield relative to the lock collar and hold the device shield relative to the lock collar in the first position against the bias of a pre-loaded spring positioned between the lock collar and device shield and urging the device shield toward the second position, wherein the device shield is caused to disengage from the lock collar by the syringe as the device shield moves proximally enabling the device shield to move distally to the second position, wherein the device shield includes one or more retention arms to retain the device shield in the first position, wherein the one or more retention arms are radially deflectable by the syringe to disengage from the lock collar as the device shield moves proximally.
 2. The needle guard of claim 1 further comprising a needle shield assembly releasably coupled to the device shield.
 3. The needle guard of claim 2 wherein the needle shield assembly is configured to prevent proximal movement of the device shield.
 4. The needle guard of claim 3 wherein the needle shield assembly comprises a rigid needle shield and a soft needle shield received in the rigid need shield.
 5. The needle guard of claim 4 wherein the rigid needle shield includes an annular ring releasably retainable by retaining arms of the device shield.
 6. The needle guard of claim 1 wherein the lock collar includes one or more tabs, wherein the one or more retention arms engage the one or more tabs to retain the device shield in the first position.
 7. The needle guard of claim 6 wherein the one or more retention arms having one or more holes there through forming a seat that rests on a surface of the one or more tabs.
 8. A needle guard couplable to a ready-to-fill syringe, the ready-to-fill syringe including a body, a step down region at a distal end of the body, a neck extending from the step down region and a bulbus formed on the neck, the needle guard comprising a lock collar couplable to a neck of a ready-to-fill syringe, wherein the lock collar includes retaining arms with pads at their ends that interface with the neck of the syringe and abut a bulbus on the neck to prevent distal movement of the lock collar relative to the neck beyond the bulbus, and a device shield biased to move relative to the lock collar from a first position in which a syringe sharp extends beyond the device shield to a second position in which the syringe sharp is covered by the device shield, the lock collar and device shield being configured to engage to prevent movement of the device shield relative to the lock collar and hold the device shield relative to the lock collar in the first position against the bias of a pre-loaded spring positioned between the lock collar and device shield and urging the device shield toward the second position, wherein the device shield is caused to disengage from the lock collar by the syringe as the device shield moves proximally enabling the device shield to move distally to the second position.
 9. The needle guard of claim 7 wherein the seat disengages from the surface of the tab as the one or more retention arms are radially deflected by the syringe as the device shield moves proximally.
 10. The needle guard of claim 9 wherein the one or more retention arms includes a rib that interacts with a syringe step down region to radially deflect the one or more retention arms.
 11. The needle guard of claim 1 further comprising a tactile feedback mechanism indicating activation of the device shield.
 12. The needle guard of claim 1 further comprising an audio feedback mechanism indicating activation of the device shield.
 13. The needle guard of claim 11 wherein the tactile feedback mechanism includes one or more feedback arms extending from the device shield and deflectable by the syringe to push through one or more feedback tabs on the device shield as the device shield moves proximally.
 14. The needle guard of claim 12 wherein the audio feedback mechanism includes one or more feedback arms extending from the device shield and deflectable by the syringe to push through one or more feedback tabs on the device shield as the device shield moves proximally.
 15. A syringe assembly comprising a syringe, a needle extending from a distal end of the syringe, and a needle guard coupled to the distal end of the syringe, the needle guard including a lock collar couplable to a neck of the syringe, and a device shield biased to move relative to the lock collar from a first position in which a syringe sharp extends beyond the device shield to a second position in which the syringe sharp is covered by the device shield, the lock collar and device shield being configured to engage to prevent movement of the device shield relative to the lock collar and hold the device shield relative to the lock collar in the first position against the bias of a pre-loaded spring positioned between the lock collar and device shield and urging the device shield toward the second position, wherein the device shield is caused to disengage from the lock collar by the syringe as the device shield moves proximally enabling the device shield to move distally to the second position, wherein the device shield includes one or more retention arms to retain the device shield in the first position, wherein the one or more retention arms are radially deflectable by the syringe to disengage from the lock collar as the device shield moves proximally.
 16. The syringe assembly of claim 15 further comprising a needle shield assembly releasably coupled to the device shield.
 17. The syringe assembly of claim 16 wherein the needle shield assembly is configured to prevent proximal movement of the device shield.
 18. The syringe assembly of claim 16 wherein the needle shield assembly comprises a rigid needle shield and a soft needle shield received in the rigid need shield.
 19. The syringe assembly of claim 17 wherein the rigid needle shield includes an annular ring releasably retainable by retaining arms of the device shield.
 20. The syringe assembly of claim 15 wherein the lock collar includes one or more tabs, wherein the one or more retention arms engage the one or more tabs to retain the device shield in the first position.
 21. The syringe assembly of claim 20 wherein the one or more retention arms having one or more holes there through forming a seat that rests on a surface of the one or more tabs.
 22. A syringe assembly comprising a syringe, a needle extending from a distal end of the syringe, and a needle guard coupled to the distal end of the syringe, the needle guard including a lock collar couplable to a neck of the syringe, wherein the lock collar includes flexible arms with pads at their ends that interface with the neck of the syringe and abut a bulbus to prevent distal movement of the lock collar relative to the neck beyond the bulbus, and a device shield biased to move relative to the lock collar from a first position in which a syringe sharp extends beyond the device shield to a second position in which the syringe sharp is covered by the device shield, the lock collar and device shield being configured to engage and hold the device shield relative to the lock collar in the first position against the bias urging the device shield toward the second position, wherein the device shield is caused to disengage from the lock collar by the syringe as the device shield moves proximally enabling the device shield to move distally to the second position.
 23. The syringe assembly of claim 21 wherein the seat disengages from the surface of the tab as the one or more retention arms are radially deflected by the syringe as the device shield moves proximally.
 24. The syringe assembly of claim 23 wherein the one or more retention arms includes a rib that interacts with a syringe step down to radially deflect the one or more retention arms.
 25. The syringe assembly of claim 15 further comprising a tactile feedback mechanism indicating activation of the device shield.
 26. The syringe assembly of claim 15 further comprising an audio feedback mechanism indicating activation of the device shield.
 27. The syringe assembly of claim 15 wherein the device shield includes feedback arms to indicate activation of the device shield , wherein the feedback arms extending from the device shield and being deflectable by the syringe to push through one or more feedback tabs on the device shield as the device shield moves proximally.
 28. The needle guard of claim 21 wherein the one or more retention arms having a second one or more holes there through forming a second seat that rests on a surface of the one or more tabs to prevent movement of the device shield relative to the lock collar and hold the device shield relative to the lock collar in the second position.
 29. The needle guard of claim 7 wherein the one or more retention arms having a second one or more holes there through forming a second seat that rests on a surface of the one or more tabs to prevent movement of the device shield relative to the lock collar and hold the device shield relative to the lock collar in the second position. 